Calcined Clay vs Expanded Shale-What’s the Difference

Both Calcined Clay and Expanded Shale topdressing products are made from natural occurring earthen materials that are found in specific locations in the United States. After these materials are mined, they are both processed and heated at very high temperatures to stabilize their physical structures. This protects the physical integrity of the individual particles against the wear and breakdown that can occur from the abrasive actions performed while maintaining the surface of a skinned infield. The heating process also affects the absorption rates of water into these products.

These materials should only be used on the surface of your infield skinned areas where they supply the biggest benefits for the best value. Incorporating or tilling these into your infield soils drastically decreases their value and contributions to the overall performance of the infield skin. A topdressing layer of 1/4″ to 3/8″ on the surface of your infield helps in managing your infield’s moisture, creating the perfect sliding surface and really makes maintaining your infield much easier.

You can use these materials individually as a topdressing or blend them together at the ratio you believe provides for the best performance on your infield surface.

Want to learn more? Sign up for tips & specials.

Paul Zwaska

A former head groundskeeper for the Baltimore Orioles, Paul has been with Beacon Athletics for two decades. Among his many accomplishments, he authored Groundskeeper University, the first online ballfield maintenance training venue and continues to find innovative ways to help groundskeepers.